[Mlir-commits] [mlir] [mlir] Add property combinators, initial ODS support (PR #94732)

[Christian Ulmann]

================
@@ -88,13 +138,31 @@ class Property<string storageTypeParam = "", string desc = ""> {
   // - `$_storage` is the storage type value.
   // - `$_reader` is a `DialectBytecodeReader`.
   // - `$_ctxt` is a `MLIRContext *`.
+  //
+  // This will become the body of a function returning LogicalResult.
+  // There is an implicit `return success()` at the end of this function.
+  //
+  // When this code executes, `$_storage` will be initialized to the property's
+  // default value (if any, accounting for the storage type override).
   code readFromMlirBytecode = [{
     if (::mlir::failed(readFromMlirBytecode($_reader, $_storage)))
       return ::mlir::failure();
   }];
 
-  // Default value for the property.
-  string defaultValue = ?;
+  // Base definition for the property. (Will be) used for `OptionalProperty` and
+  // such cases, analogously to `baseAttr`.
+  Property baseProperty = ?;
+
+  // Default value for the property within its storage. This should be an expression
+  // of type `interfaceType` and should be comparable with other types of that
+  // interface typ with `==`. The empty string means there is no default value.
+  string defaultValue = "";
+
+  // If set, the default value the storage of the property should be initilized to.
+  // This is only needed when the storage and interface types of the property
+  // are distinct (ex. SmallVector for storage vs. ArrayRef for interfacing), as it
+  // will fall back to defaultValue when unspecified.
----------------
Dinistro wrote:

```suggestion
  // will fall back to `defaultValue` when unspecified.
```

https://github.com/llvm/llvm-project/pull/94732